Audi’s $100,000 Diesel Sedan Charges Like Rogue Elephant

A 2014 Audi A8 L TDI. Starting at $82,500, it is pricier than the six-cylinder long-wheelbase A8 ($78,800), but less than the 4.0-liter eight cylinder ($87,600). Source: Audi of America, Inc. via Bloomberg

June 27 (Bloomberg) -- When it comes to executive-class
sedans, you can bet that automakers are showing off their most
luxurious interiors and very latest technologies. Traditionally
you could also bet on those full-sized cars sucking down gas by
the barrelful.

That dynamic is changing, and quickly. Audi has just
released a diesel-powered version of its A8 long-wheelbase
sedan, giving the company a more efficient offering against
hybrid models from Lexus, Mercedes-Benz and BMW.

On the highway, the A8 L TDI is the class’s new gas mileage
king, getting 36 miles per gallon. (It sees 24 in stop-and-go
traffic.) Compare that to the top-of-the-line Lexus hybrid, the
LS 600h L, which manages only 19 city and 23 highway. Mercedes
also sells a diesel version of its iconic S-Class; it gets 21
and 31.

The A8 TDI starts at $82,500, making it pricier than the
six-cylinder, long-wheelbase A8 ($78,800), but less than the
4.0-liter eight cylinder ($87,600). If you still prefer a
whopping big engine, open your wallet for the W-12 model
($135,900).

The thought of mating a shiny car like the A8 with a diesel
engine may seem odd. But the VW Group’s turbocharged direct
injection (TDI) engines, which use ultra-low-sulfur fuel, are
found on vehicles ranging from the VW Passat to the Audi Q7 SUV,
and the powerplant is much loved. Diesels tend to make converts
of drivers. Find a TDI driver and it’s likely he or she will
proselytize.

Diesel Offensive

Audi is pushing diesel across its lines. By the end of the
summer, TDI versions of the A6 and A7 sedans and the Q5 SUV will
also be available. Perhaps diesel’s time in America has finally
arrived.

While the A8’s 3.0-liter six-cylinder TDI has only 240
horsepower, it has 407 pound-feet of torque. The car doesn’t
leap forward with ferocity -- 60 miles per hour takes 6.4
seconds -- but it pulls up hills like a rogue elephant. It is
never very loud, and it never seems to strain.

For my test drive, I had a special route in mind: A 660-mile, round trip from New York to northeast Vermont. Starting
with just under a full tank, I figured I would need to fill up
only once.

The beginning of the trip was a wretched attempt to escape
Manhattan in the late evening bumper-to-bumper traffic and a
torrential rain. The car had a defective driver-side wiper
blade, leaving streaks of smeared water directly in my line of
vision. All that fancy technology, felled by a strip of bad
rubber.

Traffic Sense

It was, however, an ideal time to try out the car’s
adaptive cruise control with stop-and-go functionality. Set the
system and the car will adjust its speed according to traffic,
inching forward or coming to a full stop when necessary.

After all, a major aspect of these executive-class cars is
their technology, and both the A8 and the BMW 7 Series will be
facing down the totally redesigned 2014 model-year Mercedes S-Class. The S-Class’s new adaptive cruise control is semi-autonomous and will even keep the car centered in its lane on
curves. (I’ll test drive the new Mercedes soon.)

To be honest, I’m leery of all this self-driving
technology, fearing that the car won’t in fact stop on its own,
and that I’ll be left explaining to the traffic police that the
rear-ending accident isn’t my fault, but the car’s.

Passive Driving

So the first time the Audi surged toward the bumper of
another car, I kept my foot hovered over the brake. I got closer
and closer and...it stopped. Over the next hour the function
made the traffic more tolerable. Still, it tends to make you
less aware of your surroundings, more expectant that somehow the
car will step in and save you.

Finally I cleared the traffic and let the A8 diesel do what
it does best: Eat up highway miles. The all-wheel-drive sedan is
stable, comfortable and utterly confident on the open road, even
in the rain. I engaged the massaging seat function and blasted
the $6,300 Bang & Olufsen sound system.

The LED headlights lit my way gorgeously and I made the
destination, East Burke, around 1 a.m., behind schedule because
of the rain, but with just under half a tank of gas.

In more than 600 miles of mixed motoring, with an average
speed of 43 mph, the car saw 28.5 mpg, almost exactly its EPA
rating. Over 300 miles of freeway driving, I got just under 33
mpg.

The average buyer of an executive-class sedan won’t choose
a car for its mpg rating. Technology, comfort and great looks
will still matter most. Nonetheless, it’s hard to imagine why
you wouldn’t choose the diesel engine. Drivers will give up very
little -- except that extra stop at the gas pump on long road
trips.

The 2014 Audi A8 L TDI at a Glance

Engine: 3.0-liter six-cylinder diesel with 240 horsepower

and 407 pound-feet of torque.

Transmission: Eight-speed automatic.

Speed: 0 to 60 mph in 6.4 seconds.

Gas mileage per gallon: 24 city, 36 highway.

Price as tested: $99,445.

Best features: Powers up hills, great highway mileage.

Worst feature: That defective wiper blade.

Target buyer: The luxury-loving road tripper.

(Jason H. Harper writes about autos for Muse, the arts and
leisure section of Bloomberg News. The opinions expressed are
his own.)

Muse highlights include Rich Jaroslovsky on gadgets and
Lance Esplund on art.

To contact the writer of this column:
Jason H. Harper at Jason@JasonHharper.com or follow on
Twitter @JasonHarperSpin.